Some of electric apparatuses are equipped with a function to detect an electric current and a function to cut off the electric current. Atypical example of the electric apparatus equipped with the function to detect the electric current and the function to cut off the electric current is exemplified by an overcurrent relay (refer to, e.g., Patent document 1).
Further, in recent years, there has been a request for reducing a power consumption due to a rise in demand for electric power and in terms of taking into consideration the terrestrial environment. One of schemes for reducing the power consumptions is exemplified by visualization of the power consumption of the electric apparatus for a user. Information on the power consumption of the electric apparatus enables an efficient operation of the electric apparatus to be actualized. For example, in the case of an office, the information on the power consumption of an OA (Office Automation) apparatus is useful in terms of settling upon a plan for implementing an efficient work. This being the case, such an attempt has been made that, e.g., current sensors are installed in a distribution switchboard and a table tap, and the respective electric apparatuses are controlled corresponding to the power consumptions of the electric apparatuses connected to subordinate components of the distribution switchboard and the table tap (refer to, e.g., Patent document 2).